Advances in studies of nuclei far from stability

Abstract

Studies of the structure and decay modes of nuclei far from stability have yielded many new insights which were not seen in nuclei near the line of p stability. The results of recent experimental and theoretical investigations are presented and the new insights being gained are discussed. Some of the highlights described include groundstate proton radioactivity, &delayed 2n, 3n and 2p decays, the coexistence of states built on quite different nuclear shapes in the same nucleus, new regions of strongly deformed nuclei, and the importance of the reinforcement of proton and neutron shell gaps on the shape of a nucleus.

β-Delayed Neutron Spectroscopy Using Trapped Radioactive Ions

“…Both neutron branching ratios and energy spectra are required for nuclear reactor kinetics calculations for reactor safety studies [1,[8][9][10], and are important for future Generation IV reactor designs [11]. Delayed-neutron measurements aid in the understanding of the nuclear structure of neutronrich nuclei [12][13][14][15] and are needed to improve nuclearstructure models [16] and empirical predictions [17] used to determine the properties of nuclei for which no data exists. High quality data also has the potential to help determine neutron-capture rates [18,19] for neutron-rich isotopes needed to understand the non-equilibrium phase of r-process nucleosynthesis [20][21][22] and to support the stockpile stewardship mission [23,24].…”

Nuclear ground state spins of short-lived strontium isotopes

“…This series of sDins includes two controversial cases, 93Sr and 97Sr, where first spin assignments from nuclear spectroscopy were revised later on [3 7]. Among these, 97Sr deserves special attention since the odd-mass isotones with N = 59 are considered to be an excellent testing ground for nuclear models because of their unique situation in the narrow range of neutron numbers where shape coexistence is indicated [7,8].Our hfs measurements have been performed 5s 2SI/2 -5p 2F3/2 transition in the (l = 407.8 nm) of the Sr § ion. We used the technique of cellinear fast-beam laser spectroscopy and the experimental procedure is similar to that one described in ref.…”

Summary remarks and future prospects for on-line nuclear orientation

“…The importance of these discoveries and the broad ranges of unexplored nuclear terrain still farther from stability have made this field a major frontier in nuclear science (see reviews by Hansen [3] and Hamilton jrt ^j_. [4]). Mow, as we will show, nuclear orientation facilities on-line with on-line separators can have very significant impacts on the quality and quantity of data in unexplored regions 68 far from stability.…”